Dead Letter Queues: Where Your Poison Messages Actually Go
Every message-driven system eventually meets its poison message: one malformed payload, one downstream bug, one record that will never process successfully — retried forever, burning CPU, and in the worst designs blocking every message queued behind it. The dead letter queue is the answer, but “just add a DLQ” hides three decisions: how many attempts before giving up, what counts as an attempt, and who gets woken up when something lands in the DLQ. Get any of them wrong and the DLQ is theater. ...